Ice age happens!

(corridor leading to halls 9 & 10)

Ice ages are not a recent phenomenon, but have accompanied the earth for over 2 billion years. The causes of these climatic fluctuations are still poorly understood. The first Ice Age occurred 2.5 billion years ago. Photosynthesis by bacteria released increasing amounts of oxygen into the atmosphere and ozone formed. Simultaneously, the organisms used large amounts of the greenhouse gas carbon dioxide (CO2) for photosynthesis. Thus, the warming radiation was reduced, temperatures fell and the first ice caps covered the poles. The second freezing phase followed 700 million years ago. Several extremely cold phases, each lasting up to 10 million years, alternated with short warming periods and transformed the earth into snowball earth. Thick ice caps also formed 450, 360 and 300 million year ago in the Ordovician and in the Carboniferous. The cooling which led to the recent Ice Age already began some 30 million years ago. It culminated 2.8 million years ago in the Ice Age cycles, which still influence our Holocene world. The Holocene is the present warm period of the Ice Age. The preceding cold period (Würm Ice Age in Europe, Wisconsin in the USA) lasted for 100,000 years. Even our present warm period is not uniform, but accentuated by minor climatic deviations. The influence of these deviations on the history of humans is tremendous.The exhibition links the prehistoric ice ages with the modern climate change.